Tailoring the Best Positive End-Expiratory Pressure Through Invasive Right Ventricular Pressure-Volume Loops in a Patient Supported by Veno-Arterial Extracorporeal Membrane Oxygenation.

Patients undergoing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) typically suffer from cardiogenic pulmonary edema and lung atelectasis, which can exacerbate right ventricular (RV) dysfunction through an increase in lung elastance and RV afterload. Invasive mechanical ventilation settings, and positive end-expiratory pressure (PEEP) in particular, can help to improve RV performance by optimizing lung recruitment and minimizing alveolar overdistention. In this report, we present a VA-ECMO supported patient in whom in vivo RV pressure-volume (PV) loops were measured during a decremental PEEP trial, leading to the identification of an optimum PEEP level from a cardio-respiratory viewpoint. This innovative approach of tailoring mechanical ventilation settings according to cardio-respiratory physiology through in vivo RV PV loops may provide a novel way to optimize hemodynamics and patient outcomes.

Mitochondrial Oxygenation During Cardiopulmonary Bypass: A Pilot Study.

Objective: Adequate oxygenation is essential for the preservation of organ function during cardiac surgery and cardiopulmonary bypass (CPB). Both hypoxia and hyperoxia result in undesired outcomes, and a narrow window for optimal oxygenation exists. Current perioperative monitoring techniques are not always sufficient to monitor adequate oxygenation. The non-invasive COMET® monitor could be a tool to monitor oxygenation by measuring the cutaneous mitochondrial oxygen tension (mitoPO2). This pilot study examines the feasibility of cutaneous mitoPO2 measurements during cardiothoracic procedures. Cutaneous mitoPO2 will be compared to tissue oxygenation (StO2) as measured by near-infrared spectroscopy. Design and Method: This single-center observational study examined 41 cardiac surgery patients requiring CPB. Preoperatively, patients received a 5-aminolevulinic acid plaster on the upper arm to enable mitoPO2 measurements. After induction of anesthesia, both cutaneous mitoPO2 and StO2 were measured throughout the procedure. The patients were observed until discharge for the development of acute kidney insufficiency (AKI). Results: Cutaneous mitoPO2 was successfully measured in all patients and was 63.5 [40.0-74.8] mmHg at the surgery start and decreased significantly (p < 0.01) to 36.4 [18.4-56.0] mmHg by the end of the CPB run. StO2 at the surgery start was 80.5 [76.8-84.3]% and did not change significantly. Cross-clamping of the aorta and the switch to non-pulsatile flow resulted in a median cutaneous mitoPO2 decrease of 7 mmHg (p < 0.01). The cessation of the aortic cross-clamping period resulted in an increase of 4 mmHg (p < 0.01). Totally, four patients developed AKI and had a lower preoperative eGFR of 52 vs. 81 ml/min in the non-AKI group. The AKI group spent 32% of the operation time with a cutaneous mitoPO2 value under 20 mmHg as compared to 8% in the non-AKI group. Conclusion: This pilot study illustrated the feasibility of measuring cutaneous mitoPO2 using the COMET® monitor during cardiothoracic procedures. Moreover, in contrast to StO2, mitoPO2 decreased significantly with the increasing CPB run time. Cutaneous mitoPO2 also significantly decreased during the aortic cross-clamping period and increased upon the release of the clamp, but StO2 did not. This emphasized the sensitivity of cutaneous mitoPO2 to detect circulatory and microvascular changes.

Increasing cardio-thoracic productivity at Erasmus MC.

The Thoraxcenter of Erasmus MC started an improvement project in 2015 in order to increase the number of open-heart surgeries by 150 for three consecutive years (450 in total, +46%), and to decrease the access time from 12-14 to 2-3 weeks by the end of 2016. This was required to attain economy of scale in a highly competitive market. In this paper we describe the first year of the project, focusing on its structure and interventions taken, resulting in 165 additional open-heart surgeries carried out in 2016 and a significantly shorter access time of 2-3 weeks.

Preoperative anaemia and outcome after elective cardiac surgery: a Dutch national registry analysis.

BACKGROUND: Previous studies have shown that preoperative anaemia in patients undergoing cardiac surgery is associated with adverse outcomes. However, most of these studies were retrospective, had a relatively small sample size, and were from a single centre. The aim of this study was to analyse the relationship between the severity of preoperative anaemia and short- and long-term mortality and morbidity in a large multicentre national cohort of patients undergoing cardiac surgery. METHODS: A nationwide, prospective, multicentre registry (Netherlands Heart Registration) of patients undergoing elective cardiac surgery between January 2013 and January 2019 was used for this observational study. Anaemia was defined according to the WHO criteria, and the main study endpoint was 120-day mortality. The association was investigated using multivariable logistic regression analysis. RESULTS: In total, 35 484 patients were studied, of whom 6802 (19.2%) were anaemic. Preoperative anaemia was associated with an increased risk of 120-day mortality (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI]: 1.4-1.9; P<0.001). The risk of 120-day mortality increased with anaemia severity (mild anaemia aOR 1.6; 95% CI: 1.3-1.9; P<0.001; and moderate-to-severe anaemia aOR 1.8; 95% CI: 1.4-2.4; P<0.001). Preoperative anaemia was associated with red blood cell transfusion and postoperative morbidity, the causes of which included renal failure, pneumonia, and myocardial infarction. CONCLUSIONS: Preoperative anaemia was associated with mortality and morbidity after cardiac surgery. The risk of adverse outcomes increased with anaemia severity. Preoperative anaemia is a potential target for treatment to improve postoperative outcomes.

A case report of an interrupted inferior vena cava and azygos continuation: implications for preoperative screening in minimally invasive cardiac surgery.

BACKGROUND: Femoral cannulation is commonly used in minimally invasive cardiac surgery to establish extracorporeal circulation. We present a case with a finding that should be evaluated when screening candidates for minimally invasive cardiac surgery. CASE SUMMARY: A 57-year-old male patient was scheduled for minimally invasive repair of the mitral and tricuspid valve and a MAZE procedure. During surgery there was difficulty advancing the venous cannula inserted in the right femoral vein. On transoesophageal echocardiography a guidewire advanced from the femoral vein was observed entering the right atrium from the superior vena cava. Despite inserting a second venous cannula in the jugular vein, venous drainage was insufficient for minimal invasive surgery. The approach was converted to a median sternotomy with bicaval cannulation. Re-examination of the preoperative computed tomography (CT) scan showed an interrupted inferior vena cava (IVC) with azygos continuation. DISCUSSION: In patients with major venous malformations such as the interrupted IVC with azygos continuation a full sternotomy is the preferred approach. The venous system should be evaluated when screening candidates for minimally invasive mitral valve surgery with preoperative CT. Additional cues to suspect interruption of the IVC are polysplenia and a broad superior mediastinal projection on the chest radiograph, mimicking a right paratracheal mass.

Effectiveness of adherence to a preoperative antiplatelet and anticoagulation cessation protocol in cardiac surgery.

OBJECTIVES: Reduction of blood loss after cardiac surgery remains challenging. The effectiveness of adherence to a protocol on cessation of anticoagulants and platelet-inhibiting medications was investigated together with the influence of protocol violations on blood loss after surgery, use of blood products, surgical re-explorations and 30-day mortality. METHODS: Between 2009 and 2013, data were collected prospectively for all elective cardiac surgery procedures in adult patients (n = 1637). Two groups were distinguished: Group 1 adhered to the protocol for cessation or continuation of medication (n = 1287, 79%) and Group 2 violated the protocol (n = 350, 21%). RESULTS: Median blood loss was 300 ml (interquartile range 175-500 ml). Eighty patients underwent re-exploration due to blood loss (5%). Thirty-day mortality was 2% (n = 27). Protocol violation was associated with increased blood loss [median 275 ml (175-475 ml) vs 350 ml (250-612); P ≤ 0.001] and with increased average use of fresh frozen plasma (226 ml vs 139 ml; P << 0.00001), red blood cell transfusion (115 ml vs 87 ml; P = 0.081) and thrombocyte transfusions (52 ml vs 37 ml; P = 0.0082). The number of re-explorations (4% vs 6%; P = 0.39) and mortality risk (1% vs 2%; P = 0.72) did not differ. CONCLUSIONS: Balancing the benefit of continuing platelet inhibitors or anticoagulants versus cessation before surgery remains challenging. Adherence to the protocol will lead to lower blood loss and in a lower consumption of blood products although the decision to go for re-exploration and 30-day mortality does not differ compared with the protocol violation. Stopping medication does not lead to thromboembolic events.

Severe Systolic Anterior Motion After Aortic Valve Replacement and Cox MAZE Surgery.

Surgical aortic valve replacement may be complicated by severe dynamic left ventricular outflow tract obstruction and cardiogenic shock in the postoperative period. We present a patient who developed severe anterior motion following aortic valve and Cox MAZE surgery which necessitated a mitral valve replacement. doi: 10.1111/jocs.12763 (J Card Surg 2016;31:429-431).

[Antidote against local anaesthetic intoxication: new use of lipid emulsion for intravenous administration]. / Tegengif voor intoxicatie door lokale anesthetica: nieuwe toepassing van vetemulsie voor intraveneuze toediening.

Local anaesthetics are routinely used for several indications, but despite local administration their use may lead to systemic toxicity. The symptoms include numbness of the tongue, dizziness, tinnitus, visual disturbances, muscle spasms, convulsions, coma, and respiratory and cardiac arrest. Recently, an intravenous lipid emulsion was reported to act as a novel potential antidote for systemic toxicity due to local anaesthetics. We describe the application of this lipid emulsion in a 27-year-old patient with generalized seizures and coma due to local anaesthetic toxicity. She recovered quickly and was responsive again 10 minutes after the intravenous administration of the lipid emulsion.

Locoregional delivery of adenoviral vectors.

UNLABELLED: The overall median survival of patients with a malignant glioma is <1 y. Because malignant gliomas rarely metastasize outside the skull, locoregional treatment strategies, such as gene therapy, are under investigation. Recently, convection-enhanced delivery (CED) has been presented as a method to improve delivery of large molecules. The goal of this study was to evaluate whether CED improves intratumoral delivery of adenoviral vectors and compare it with single injection (SI) and multiple injection (4x, MI). METHODS: A replication-deficient adenoviral vector encoding the herpes simplex virus thymidine kinase (HSV-tk) and the human somatostatin receptor subtype 2 (sst(2)) was administered into nude mice bearing subcutaneous U87 xenografts. Tumors were injected with 1.5 x 10(9) plaque-forming units of Ad5.tk.sstr by CED, SI, or MI. Three days later, [(99m)Tc-N(4)(0-1),Asp(0),Tyr(3)]octreotate ((99m)Tc-Demotate 2) was injected intravenously to monitor the virus-induced sst(2) expression. gamma-Camera imaging was performed for in vivo imaging, and the tumor uptake of (99m)Tc-Demotate 2 was determined by gamma-counter. Furthermore, the tumor was sectioned and ex vivo autoradiography was performed. After decay of radioactivity, adjacent sections were submitted to in vitro autoradiography with (125)I-DOTA-Tyr(3)-octreotate, which was used to calculate the transduced areas. RESULTS: Transfected xenograft tissues showed high sst(2) expression and were clearly visualized with a gamma-camera. Accumulation of radioactivity was 2-fold higher in the tumors that were injected with MI compared with CED and SI (P = 0.01). CED and SI resulted in equal uptake of radioactivity in the tumors. The measured areas of transduction in ex vivo and in vitro autoradiographs showed a high concordance (r(2) = 0.89, P < 0.0001). The maximum area of transfection was significantly larger after MI than after CED (P < 0.05) or SI (P = 0.05). Also, the measured volume of distribution was twice as high after administration of Ad5.tk.sstr by MI (56.6 mm(3)) compared with SI (25.3 mm(3)) or CED (26.4 mm(3)). CONCLUSION: CED does not increase adenoviral vector distribution in a glioma xenograft model compared with SI. Therefore, in the clinic MI is probably the most effective delivery method for the large adenoviral particle (70 nm) in malignant gliomas.

Increased glia-specific transgene expression with glial fibrillary acidic protein promoters containing multiple enhancer elements.

The ability to direct transgene expression to astrocytes has become increasingly important as the roles for these cells continue to expand. Promoters consisting of the 5'-flanking region of the human or mouse glial fibrillary acidic protein (GFAP) gene have generally proved satisfactory. However, a more powerful promoter would be advantageous for several applications, such as expression of dominant negative RNAs or proteins, or for gene therapy. We investigated the possibility of increasing the transcriptional activity of the human GFAP promoter by inserting into it one or three additional copies of putative GFAP enhancer regions. The promoters enhanced with three additional copies gave 75-fold higher LacZ expression levels upon plasmid transfection into GFAP-expressing U251 cells than the parental gfa2 promoter. Surprisingly, in a transgenic mouse model, the enhanced promoters resulted in no or only very low expression of marker genes, probably caused by toxicity. When various cell lines were infected with replication-deficient adenoviral vectors, the enhanced promoters gave LacZ expression levels that were approximately 10-fold higher than those with the parental gfa2 promoter, while retaining specificity for GFAP-expressing cells. Injection of the adenoviral vectors carrying the enhanced promoters into nude mouse brain showed that LacZ expression was limited to GFAP-positive cells. We conclude that gfa2 enhanced promoters are useful for production of short-term, glia-specific, high expression levels of genes in an adenoviral context. Adenoviral vectors containing these enhanced promoters may be useful in glioma gene therapy.